Khan.scratchpad.disable(); For every level Tiffany completes in her favorite game, she earns $780$ points. Tiffany already has $500$ points in the game and wants to end up with at least $2250$ points before she goes to bed. What is the minimum number of complete levels that Tiffany needs to complete to reach her goal?
Solution: To solve this, let's set up an expression to show how many points Tiffany will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Tiffany wants to have at least $2250$ points before going to bed, we can set up an inequality. Number of points $\geq 2250$ Levels completed $\times$ Points per level $+$ Starting points $\geq 2250$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 780 + 500 \geq 2250$ $ x \cdot 780 \geq 2250 - 500 $ $ x \cdot 780 \geq 1750 $ $x \geq \dfrac{1750}{780} \approx 2.24$ Since Tiffany won't get points unless she completes the entire level, we round $2.24$ up to $3$ Tiffany must complete at least 3 levels.